OK you download the mod. Unzip in the mod directory, then activate it. then go and create a pretender for your nation. Then you go to saved games directory/newlords and there is your pretender .2h file you send that via email at
pretenders@llamaserver.net put as a subject of the email the exact name of the game(the way you see it in the link so: ATCU_A_Totally_Civil_Union)
Then after all the pretenders have been sent you will receive an email with the first turn attached to it. Create a new folder in the savedgames directory named by your preference, and save the first turn .trn file in it. Then you start dominions click start game and there will be a game named the way you named the folder. Click on it. Play it out, click end turn. then open the same folder that you created and there will be a .2h file in it (and the .trn file) so you just reply to the email that you received for the first turn attaching your .2h file.
Hope I didn't miss anything